New field test advances Ebola diagnoses

Researchers have developed a rapid, cheap and reliable field test to detect two strains of the Ebola virus.

The study, carried out by Canadian, Congolese, Dutch, Gabonese and German scientists, was published on 15 November in the Journal of Infectious Diseases.

In 30 minutes, the test detects viral proteins of Zaire and Sudan Ebola virus from samples of patients' urine and serum using an 'immunofiltration assay'. The samples are chemically deactivated to prevent infection to workers.

The researchers had originally wanted to develop a test for all strains of the virus, but they found that it was only sensitive to the Zaire and Sudan strains.

They tested the method in the field using samples obtained from an outbreak of Ebola hemorrhagic fever in Mbomo and Mbanza in the Republic of the Congo in December 2003.

"Due to its relatively low price, and as no technical equipment is needed, this assay could be helpful for developing countries to make early diagnoses at Ebola virus outbreaks," Andreas Lucht, lead researcher from the Germany-based BundeswehrInstituteofMicrobiology, told SciDev.Net.

"It might be useful especially in endemic areas where the test could be done immediately onsite," Lucht adds.

He says that the assay has already been used in cooperation with the WHO and the Ministry of Health of the Republic of the Congo, and local staff have been trained to use the test in areas without electricity or running water.

The team are now trying to develop a more sophisticated version of the test to detect antibodies to the virus in the later stages of infection.

"Previous outbreaks have shown that some patients might present at the hospital or healthcare station several days after onset of symptoms. In the later stages of the disease it can be impossible to detect viral [protein]," says Lucht.

Morad Ahmed, a professor of medicine at Tanta University, Egypt, says "This long-awaited diagnostic tool that can use urine as a sample will play an important role in response management for future Ebola outbreaks as it is safer than using blood samples, and culturally acceptable to the African community."

Daniel Okenu, a Nigerian scientist at the US-based Morehouse School of Medicine, told SciDev.Net "This new development could be considered as an ideal model for north-south science cooperation."